Fix stack_status YAQL expression for non existent stacks
Fix stack_status YAQL expression for non existent stacks

We retry few times in 'wait_for_stack_does_not_exist' workflow.
However, it's possible that the stack has dissapeared by the time
we list stacks after the delay.

Change-Id: Ic85782a4942eca09f92b4212930881878638fac6
Closes-Bug: #1812810

openstack/tripleo-common,openstack/tripleo-common